#include "nonblocksockets.h"

#include "logging.h"

#include <stdlib.h>

static uint32_t get_peer_ip(TCPsocket sock) {

	IPaddress *addr = SDLNet_TCP_GetPeerAddress(sock);

	return SDLNet_Read32(&addr->host);

}

static bool connection_is_local(TCPsocket sock) {

	return get_peer_ip(sock) == (uint32_t)((127UL<<24)+1); // 127.0.0.1

}

void flib_nbsocket_close(NonBlockSocket *nbsockptr) {

	NonBlockSocket nbsock = *nbsockptr;

	if(nbsock!=NULL) {

		SDLNet_DelSocket(nbsock->sockset, (SDLNet_GenericSocket)nbsock->sock);

		SDLNet_TCP_Close(nbsock->sock);

		SDLNet_FreeSocketSet(nbsock->sockset);

	}

	free(nbsock);

	*nbsockptr = NULL;

}

NonBlockSocket flib_nbsocket_accept(TCPsocket listensocket, bool localOnly) {

	NonBlockSocket result = NULL;

	if(!listensocket) {

		flib_log_e("Attempt to accept a connection on a NULL socket.");

		return NULL;

	}

	while(result==NULL) {

		TCPsocket sock = SDLNet_TCP_Accept(listensocket);

		if(!sock) {

			// No incoming connections

			return NULL;

		}

		if(localOnly && !connection_is_local(sock)) {

			flib_log_i("Rejected nonlocal connection attempt from %s", flib_format_ip(get_peer_ip(sock)));

			SDLNet_TCP_Close(sock);

		} else {

			result = malloc(sizeof(_NonBlockSocket));

			if(result==NULL) {

				flib_log_e("Out of memory!");

				SDLNet_TCP_Close(sock);

				return NULL;

			}

			result->sock = sock;

			result->sockset = SDLNet_AllocSocketSet(1);

			if(result->sockset==NULL) {

				flib_log_e("Out of memory!");

				SDLNet_TCP_Close(sock);

				free(result);

				return NULL;

			}

			SDLNet_AddSocket(result->sockset, (SDLNet_GenericSocket)result->sock);

		}

	}

	return result;

}

int flib_nbsocket_recv(NonBlockSocket sock, void *data, int maxlen) {

	if(!sock) {

		flib_log_e("Attempt to receive on a NULL socket.");

		return -1;

	}

	int readySockets = SDLNet_CheckSockets(sock->sockset, 0);

	if(readySockets>0) {

		int size = SDLNet_TCP_Recv(sock->sock, data, maxlen);

		return size>0 ? size : -1;

	} else if(readySockets==0) {

		return 0;

	} else {

		flib_log_e("Error in select system call: %s", SDLNet_GetError());

		return -1;

	}

}